Cable termination



Feb. '13, 1968 Filed Sept. 10, 1965 C. HARRIS ETAL CABLE TERMINATION [Ol I 2 Sheets-Sheet 1 FIG.2

CECI L HARRIS v REED H. JOHNSTON INVENTORS.

ham 1 mp 5W ATTORN EYS Feb. 13, 1968 v v c. HARRIS ETAL 3,369,072

CABLE TERMINATION Filed se t; 10, 1965 2 Sheets-Sheet 2 PIC-3.3

CECIL HARRIS REED H. JOHNSTON INVENTORS.

7721M 1M M2 BMW ATTORNEYS United States Patent 3,369,072 CABLE TERMINATION Cecil Harris, Lexington, and Reed H. Johnston, Wellesley,

Mass, assignors, by mesne assignments, to Simplex Wire and (Iable Company, Cambridge, Mass., 21 corporation of Massachusetts Filed Sept. 10, 1965, Ser. No. 486,475 7 (Ilaims. (Cl. 174-75) ABSTRACT OF THE DISCLOSURE A conductor terminal is disclosed consisting of a plug adapted to be inserted into the end of a sheathed sodium conductor and being so dimensioned that it expands the conductor sheath with portions of the plug having a reduced diameter so that the resilient conductor sheath and plug become mechanically connected. The plug includes a central passage through which the sodium metal is extruded during insertion of the plug into the end of the conductor and the outer end of the plug includes a flange which butts against the end of the conductor sheath. A sleeve is provided to pass over the conductor sheath and the flange of the plug and this sleeve includes longitudinal ribs or splines. These splines pass through corresponding ridges in the plug flange to prevent relative rotation of the plug and sleeve and they also dig into the sheath of the conductor to prevent relative rotation of the sheath and sleeve. A conventional conductor is then connected to the end of the plug flange.

A method of inserting the plug into the end of the conductor is also disclosed using a gear puller and modified Kellem grip and a method for heating the plug to fuse the sheath into the grooves in the plug periphery by applying heat to a metallic cylinder connected to the central passage of the terminal plug is also disclosed.

This invention relates to electric cable termination and in particular provides a terminal construction suitable for making connection with a cable utilizing a sheathed alkali metal or alkaline earth metal conductor.

The alkali metals, alkaline earth metals and their alloys and mixtures represent an abundant source of electrically conductive materials. However, the high reactivity of these materials has generally been an obstacle to their usage as electric conductors. For example, it is difficult to make an eflicient connection with a cable utilizing such a conductor material as the presence of an oxide of the conductor metal on the surface of such a conductor greatly decreases the electrical efficiency of any connection with the conductor. Since the high chemical reactivity of these conductor materials generally requires they be sheathed with a relatively inert material, which can be either a conductive or dielectric material, the necessary presence of a sheath additionally complicates the mechanical problem of making effective electrical contact with the conductor while maintaining sheath integrity.

It is thus generally an object of this invention to provide a cable terminal for sheathed conductors which will provide eifective electrical contact with the conductor while maintaining sheath integrity.

A method for joining a special conductor, i.e., a conductor of an alkali metal, or an alkaline earth metal or of an alloy or a mixture of such metals to more conventional conductors has been disclosed in copending application Ser. No. 480,480 of Feick and Doherty. It is there disclosed that an eflicient bond between a special conductor and a more conventional conductor, such as a copper conductor, can be elfected by the interposition between the conductors to be joined of a layer of an intermediate metal, such as mercury, which allows with the 3,3fi9fi72 Patented Feb. 13, 1968 metals of each conductor at temperatures at which those metals do not alloy with each other. It is further disclosed in said copending application that the efficiency of the contact so formed is adversely affected if the bond formed between the conductor metals is fractured by mechanical stress.

It is therefore a further object of this invention to provide a cable terminal whereby a sheathed special con ductor can be joined to another, more conventional conductor by means of an intermediate metal in a joint which is isolated from mechanical stresses.

It is another object to provide a cable termination suitable for a special conductor which is sheathed in a tube formed of soft conductive or dielectric material such as copper or polyethylene.

These and other objects are accomplished by providing a cable terminal including an adaptor in the form of a plug, suitably having outside transverse dimensions approximating the corresponding dimensions of the central, special conductor core of the sheathed special conductor to be joined, and having an axial passageway extending therethrough. One end of the adaptor includes a flange, suitably having outside transverse dimensions equal to the corresponding outside dimensions of the sheath about the special conductor. The flange is longitudinally grooved at intervals about its periphery and the adaptor is necked down in the area adjacent to the flange. The terminal also includes an open-ended, tubular, outer cover-sleeve, suitably having inside transverse dimensions slightly greater than the corresponding outside dimensions of the flange, a length preferably greater than the length of the adaptor and having interior longitudinal splines which extend its length. The splines are sized and located to fit snugly into the grooves of the flange in a running fit which permits the cover to be drawn over the adaptor.

The terminal is applied to a sheathed special conductor by forcing the adaptor into the end of the cable in such a manner that its external cylindrical surface contacts the underside of the sheath for a substantial length and the flange butts up against the end of the sheath. This insertion can be facilitated by digging out some of the conductor material from the end of the sheath. During insertion of the adaptor into the end of the cable, however, it is important that the conductor metal be extruded into the central passage, and suflicient conductor metal should remain in the core to permit such extrusion and thus maximize contact area between the adaptor and special conductor core.

The cable sheath is then clamped in close proximity to the flange on the adaptor to cause it to conform to the necked-down portion of the adaptor and, while under this radial pressure, is permanently deformed, for example, by heating in the case of a thermoplastic sheath, thereby creating an effective vapor tight seal between the insulation and the adaptor. In the case of conductive sheaths, such as copper, aluminum and steel, the sheath can better be conformed by swaging and then brazing to insure a vapor tight seal. This conforming of the sheath to the necked-down portion of the adaptor also prevents longitudinal movement of the adaptor and cable relative to each other.

After the adaptor has been positioned in the end of the sheathed special conductor and sealed, the outer cover sleeve is pressed on by passing its interior splines through the grooves in the annular flange of the adaptor and continuing to draw the outer cover along the cable, thereby causing the splines to dig into the sheath until the outer end of the cover is co-planar with the outer surface of the terminal flange. In this position the splines within the cover lock the sheath and the adaptor securely together, thereby preventing angular movement of the cable and the adaptor relative to each other. After the cover is in 3 place it is preferred to fix its position longitudinally, for example, by a set screw passing through the cover into the adaptor flange.

Once the terminal is locked in place, electrical connection to the terminal can be made by various means, for example, by securing the end of a conductor into the central passage of the adaptor. A particular advantageous connections is effected by threadedly introducing a short length of copper conductor into the central passage of the adaptor whereby further connection can be made to the external portion of the copper conductor by conventional means. This method is particularly desirable since the short copper conductor can be fitted with a suitable flange designed to abut the annular flange of the adaptor and the end of the cylindrical cover, thereby preventing mechanical stress from being introduced across the adaptor-special conductor bond by the copper conductor. By properly curving the side of the flange remote from the adaptor flange a smooth overall configuration can be realized whereby flux leakage and local flux buildup are avoided.

It will be obvious that the short length of copper conductor secured in the central passage of the adaptor provides means for eflecting a wide variety of connections. For example, to splice two ends of conductor together, the ends of a single copper rod, one end having a right-hand thread and the other end having a lefthand thread are introduced into confronting adaptor passages having corresponding right and left-hand threads. A T can be formed by transversely tapping the interconnecting portion of the above splice.

It will be noted that the terminal of the present invention is particularly suited for use in connecting cables having soft sheathing into which the splines of the outer cover of the adaptor can be forced. Among these are polyolefin insulated cables, such as polyethylene insulated cables, to which the terminals of the present invention are easily applied. However, cables sheathed with other soft or malleable conductive or dielectric materials can also be joined by means of the present invention.

The high reactivity of the metals of the special conductors make it imperative that the adaptor seals, both internal and external, be especially eflicient. One method of sealing the central passage of the adaptor is by inserting a small, tight fitting, plug into the passage and pressing it against a raised shoulder therein. Such a plug can be held in place, for example, by a backing screw threadedly retained within the passage.

When a polyolefin-sheathed special conductor is connected by means of the present invention the external seal between the adaptor and the insulation can often be effected by merely heating the sheathing overlying the area of reduced adaptor diameter adjacent to the adaptor flange while this portion of the insulation is under radial compression. This heating can be applied externally but it is preferred to apply it from within the adaptor whereby the heat reaches the surface upon which the seal is desired without first having to pass through the entire sheathing. Such internal heating can usually be accomplished without causing melting of the metallic conductor ,due to the wide differential between the thermal conductivities of the metal and the sheathing.

Another means for effecting a vapor tight seal between the adaptor and the sheathing, for example, is an intermediate polymer for polymerizable material which can be employed for bonding the sheathing to the adaptor by coating the adaptor prior to insertion into the end of the cable. This method most frequently requires some heating to affect the desired bond. Heat can be introduced to the central passage of the adaptor by various means. One such method includes engaging a small metallic terminal in the end of the central passage and introducing heat pulses through it. Alternatively, pyrotechnic, chemical heat sources can be used to provide the required heating.

The terminals of the present invention are particularly suited for use in connection with the method for bonding special conductors to more conventional conductors, disclosed in copending application Ser. No. 480,480 of Feick and Doherty, above referred to. In accordance with that application an intermediate metal is coated on the adaptor prior to insertion into the end of the cable. The coating should extend up into the central passage of the adaptor, at least to the point where the central passage will be sealed. A suitable coating, for example, can be deposited on an adaptor by immersing it in an acidic solution of mercuric nitrate and nitric acid.

For a further description of the present invention reference is made to the annexed drawings of which:

FIGURE 1 is an exploded elevation, partly in section, of a cable terminal according to the present invention also showing a suitable connection to said terminal.

FIGURE 2 is an elevation, partly in section, showing an apparatus suitable for applying the terminal shown in FIGURE 1 to a sheathed special conductor.

FIGURE 3 is an enlarged view, partly in section, of a portion of FIGURE 2.

FIGURE 4 is an elevation, partly in section, showing a sheathed special conductor with the terminal of FIG- URE 1 attached to the end thereof and connected to another conductor.

FIGURE 5 is a section taken along lines 55 in FIG- URE 4.

Referring more particularly to FIGURE 1, the reference numeral 10 designates a terminal suitable for connection with the end of a sheathed special conductor in accordance with the present'invention. Terminal 10 includes an adaptor 12, a cover 14, a sealing plug 16 and a backing screw 18. A portion of a conventional conductor 20 suitable for connection to terminal 10 is also shown.

Adaptor 12 is somewhat cylindrical having an outside diameter equal to the diameter of the special conductor portion of the cable to which it is to beconnected. One end of adaptor 12 terminates in an annular flange 22 having an outside diameter equal to the outside diameter of the sheathed special conductor. Annular flange 22 includes four longitudinal grooves 24 which can be seen by reference to FIGURES 2 and 5 and a tapped, radial bore 26 into which a setscrew 28 can be threaded. Adaptor 12 includes an axial passage 30 which is threaded from'the flanged end of adaptor 12 through a major portion of the length of passage 30. Passage 30 also includes a shoulder 32 of reduced inside diameter in the area intermediate the threaded portion of passage 30 and the unflanged end of adaptor 12. The end of passage 30 remote from flange 22 is expanded forming a sharp, circular edge with such end of adaptor 12.

The cylindrical portion of adaptor 12 is necked down, i.e., it is slightly undercut, in the area adjacent to flange 22, and this necked-down portion, indicated in the drawings by numeral 34, also includes a plurality of small ridges 36 extending around the periphery of portion 34. Sealing plug 16 is sized to fit closely within passage 30 and its forward end is tapered to seat against shoulder 1 32 thereby sealing passage 30. Sealing plug 16 is held tightly in place by a backing screw 18 threadedly engaged in passage 30.

Cover 14 is generally cylindrical and hollow having an inside diameter slightly greater than the outside diameter of flange 22. The length of cover 14 is greater than that of adaptor 12 and it includes four interior splines 38 which extend parallel to the axis of cover 14 over its entire length. Splines 38 are sized and positoned to correspond to the longitudinal grooves 24 in flange 22 so that cover 14 can be drawn over flange 22 and rotational movement of one with respect to the other is prevented by splines 38 seated in grooves 24.

A small threaded aperture 40 adjacent one end 42 of cover 14 provides a means whereby cover 14 and adaptor 12 can be prevented from longitudinal movement with respect to each other by setscrew 28. Aperture 40 can be brought into register with bore 26 when end 42 of cover 14 is flush with the flanged end of adaptor 12 to permit setscrew 28 to be engaged in both aperture 40 and bore 26.

Connecting conductor 20 includes a threaded end portion 44 dimensioned to be threadedly received in passage 30 through the flanged end of adaptor 12 to contact the outer end of backing screw 18. An integral flange 46 is preferably formed on conductor 20immediately adjacent to threaded portion 34. Flange 46 has a diameter equal to the outside diameter of the cover 14 of the terminal to which it is attached and is designed to abut; the outer surface 48 of flange 22 and the exposed end 42 of cover 14.

Referring now to FIGURE 2,'t-here is shown an apparatus suitable for applying adaptor 12 to a sheathed special conductor 50. Conductor 50 is held by a Kellem gripper 52, i.e., a tubular basket of interwoven, spaced wires which when stretched becomes reduced in diameter. Gripper 52 is drawn over the end of conductor 50 and moved along conductor 50 a short distance. The end of gripper 52 remote from the end of conductor 50 is secured to conductor 50 by a hose clamp 54. The other end of gripper 52 is secured to a flange 56, and a flat annular collar 58 having an inside diameter slightly greater than cable 50 but less than the outside diameter of flange 56 is slidably mounted on gripper 52 between flange 56 and hose clamp 54.

Pressure is applied to adaptor 12 along the axis of cable 56 by a gear-puller 60 which includes a rod 62 which terminates at one end in a hexagonal head 64, which is affixed to rod 62, and at the other end in a rectangular hollow box 66 having a pair of open opposite sides. The connection between rod 62 and box 66 permits their relative rotational movement but prevents longitudinal movement of rod 62 with respect to box 66.

A yoke 70 is threadedly engaged on rod 62 intermediate hexagonal head 64 and box 66 to which a pair of arms 72 are pivotally secured by means of connecting links 74 which pass through eyelets 76 extending from opposite sides of yoke 70. Arms 72 have a somewhat fish-hook appearance, the hooked portions 78 being on the ends of arms 72 remote from yoke 70 and inclined towards each other. Gear-puller 60, it Will be evident, except for box 66 is entirely conventional.

The flanged end of adaptor 12 fits into a countersunk passage 68 in the side of rectangular box 66 opposite rod 62. Passage 68 receives adaptor 12, preventing rotational movement thereof, and also permits access to the central passage 30 of adaptor 12 from within box 66.

In applying adaptor 12 to the end of a sheathed special conductor 50, such as a conductor 50 having a special conductor, e.g., sodium, core 49 and a dielectric, e.g., low denisty polyethylene, tubular sheath 51, gripper 52 is first positioned on conductor 50 as described above. Adaptor 12 with sealing plug 16 and backing screw 18 removed is then positioned at the end of conductor 50 with its sharp-edged, unflanged end adjacent to the surface of contact between sodium conductor 49 and polyethylene sheath 51. Gear-puller 60 at the time receives adaptor 12, the flanged end of which is seated against a shoulder in passage 68 in box 66. The hooked portions 78 of both arms 72 are then placed on the side of the flange 58 of gripper 52 remote from the end of conductor 50 into which adaptor 12 is to be inserted. Rod 62'is rotated causing yoke 70 to move toward head 64 until the hooked portions 78 of arms 72 are brought tight against flange 58. Once gear-puller 66 is firmly positioned a suitable wrench is applied to hexagonal head 64 causing further rotation of rod 62 and consequent movement of yoke 70 toward hexagonal head 64 which in turn pulls on flange 58 advancing conductor 50 toward box 66 and causing adaptor 12 to be forced axially into the end of conductor 50. Sodium metal displaced by the insertion of adaptor 12 into the end of conductor 50 is extruded through passage 30 in adaptor 12 and can be removed from the hollow center of box 66. Rod 62 is rotated until the polyethylene sheath 51 of conductor 50 abuts flange 22 of adaptor 12 at which time passage 30 is sufficiently cleaned of extruded metal to enable the insertion of sealing plug 16 until it contacts shoulder 32 and backing screw 18 is immediately inserted to hold sealing plug 16 firmly in place.

Once passage 30 is sealed by the insertion therein of sealing plug 16 and backing screw 18 the exterior of adaptor 12 is sealed to sheath 51 by the application of heat preferably through passage 30. One means for introducing heat to passage 30 is shown in FIGURES 2 and 3. A small copper cylinder 80 having a threaded shaft 82 on one end is threaded into passage 30 without contacting the end of backing screw 18. Cylinder 80 provides a terminal whereby a heat pulse can be applied to adaptor 12 suflicient to raise the temperature of sheath 51 above its softening point thereby causing it to conform to the outer surface of adaptor 12 especially at the necked-down portion 34 of adaptor 12. The heat pulse preferably is applied by contact of cylinder 80 with a soldering iron or other heated object for a period of timed duration, the time of which is sufficient to produce the desired softening and contraction but insufficient to melt the polyethylene to a point at which it becomes fluent. It is preferable to apply a compressive force by means of a hose clamp 84 about the portion of sheath 51 overlying neck-down portion 34 of adaptor 12 during the heat-sealing step. The

presence of an adhesive on the outer surface of adaptor 12 also is preferred as an aid to bonding the sheath 51 to the adaptor 12. In addition to preventing the entry of vapors along the outside of adaptor 12 to the highly reactive metal of the special conductor, in the illustrated case, sodium core 49, the heat-sealing of sheath 51 about the necked-down portion 34 of adaptor 12 also aids in preventing longitudinal movement of adaptor 12 with respect to conductor 50.

After application of an adaptor to the end of a cable, as described above, and removal of puller 60 and gripper 52, cover 14 is then put in place by engaging splines 38 in longitudinal grooves 24 of adaptor 12 and drawing cover 14 over sheath 51 until its end 42 is flush with the outer surface 48 of flange 22. Setscrew 28 is then introduced through aperture 40 into tapped bore 26 to secure cover 14. Splines 38 not only engage cover 14 and adaptor 12 to prevent their relative rotation, but also dig deeply into sheath 51 to prevent relative rotation of sheath 51 with respect to cover 14 and hence adaptor 12. FIG- URE 4 shows a conductor 50 with a terminal 10 fully assembled in place with cover 14 attached to adaptor 12 by means of setscrew 28. The inter-relationship of flange 22 with its longitudinal grooves 24 and cover 14 with its interior splines 38 is shown by reference to FIGURE 5. Referring again to FIGURE 4, the connection of conductor 20 to terminal 10 is shown with flange 46 abutting I the outer surface 48 of the flange 22 and end 42 of cover 14.

When the use of an intermediate metal as an aid to forming a bond between the adaptor 12 and core 49 is desired, shortly prior to use adaptor 12 is cleaned thoroughly and coated with a layer of the intermediate metal,

for example, by dipping it into an acidic solution of mercuric nitrate and nitric acid. After coating adaptor 12 is applied as described above.

The terminals according to the present invention are designed to have a greater current-carrying capacity than the conductor to which they are applied. In this respecta large surface area is provided in the central passage 30 between shoulder 32 and the unflanged end of adaptor 12.

7 The threaded portion of passage 30 is designed to receive a conventional conductor of load-carrying characteristics at least equal to that of sheathed conductor 50, and here again a sufficient area of contact between adaptor 12 and threaded portion 44 of conductor 20 must be provided between the outer end of backing screw 18 and the end of passage 30 and the outer surface 48 of flange 22.

The length of cover 14 preferably is greater than the length of adaptor 12 so that adaptor 12 will be isolated over its entire length from rotational movement imparted to sheathed conductor 50 or connecting conductor 20.

A terminal according to the present invention for a conductor utilizingdielectric sheathing material is preferably provided with a copper adaptor, sealing plug and backing screw. The cover is preferably brass and, where provided, the mating flange on a connecting conventional conductor is also preferably brass. When the sheathing is of a conductive material, the terminal should be of the same material. As noted at the outset these terminals are particularly suited for use in connecting special conductors made from alkali metals, alkaline earth metals, and alloys and mixtures thereof. Examples of suitable special conductors are conductors made from sodium, sodium and potassium, sodium and lithium, sodium and calcium, calcium, calcium and lithium, and calcium, lithium and sodium. The more conventional conductors to which the terminals of the present invention are suitable for connecting include copper, aluminum, tin-plated copper, gold, silver and gold or silver-plated copper and aluminum.

When the terminals of the present invention are bonded to the sheathed special conductor by means of an intermediate metal, it is important that the cover be applied about the adaptor as soon as possible after the adaptor is inserted into the end of the cable thereby preventing a fracture of the adaptor-special conductor bond after it has been formed.

What is claimed is:

1. A cable termination for a sheathed conductor including an elongated conductive core and a tubular sheath laterally enclosing said core, which termination includes a plug sized to fit in said sheath, a flange on one end of said plug, a sleeve sized to receive said flange and said sheath, means on said sleeve for cooperating with said flange and engaging said sheath to retain said sleeve in longitudinally oriented sliding engagement with said flange and said sheath when received thereon, said plug being positioned in an end of said sheathed conductor in contact with said conductive core with said flange abutting the end of said sheath, and said sleeve overlying said flange and the end of said sheath whereby relative rotation of said sleeve with respect to said flange and said sheath is prevented.

2. A cable termination for a sheathed conductor including an elongated conductive core and a tubular sheath laterally enclosing said core, which termination includes a plug sized to fit in said sheath, a flange on one end of said plug, a necked-down portion on said plug adjacent said flange, a sleeve sized to receive said flange and said sheath, means on said sleeve for coperating with said flange and engaging said sheath to retain said sleeve in longitudinally oriented sliding engagement with said flange and said sheath when received thereon, said plug being positioned in an end of said sheathed conductor in contact with said conductive core with said flange abutting the end of saidsheath, said sleeve overlying said flange and the end of said sheath whereby relative rotation of said sleeve with respect to said flange and said sheath is prevented, and said sheath being contracted about said necked-down portion on said plug whereby relative longitudinal movement of said plug and sheathed conductor is prevented.

3. A cable termination for a sheathed conductor including an elongated conductive core and a tubular sheath laterally enclosing said core, which termination includes a plug sized to fit in said sheath, a flange on one end of said plug, a central passageway through said plug and flange, said central passagewaybeing outwardly tapered at the end of the plug away from said flange, a sleeve sized to receive said flange and said sheath, means on said sleeve for cooperating with said flange and engaging said sheath to retain said sleeve in longitudinally oriented sliding engagement with said flange and said sheath when received thereon, the end of said plug containing the outwardly tapered portion of said central passageway being forced into an end of said sheathed conductor beneath said sheathing to a position with said flange abutting the end of said sheath whereby said conductive core is displaced at the position of said plug and extruded into said passageway in contact with said plug, sealing means in said passageway whereby external access to said conductive core is prevented, said sleeve overlying said flange and the end of said sheath whereby relative rotation of said sleeve with respect to said flange and said sheath is prevented.

4. A cable termination for a sheathed conductor including an elongated conductive core and a tubular sheath laterally enclosing said core, which termination includes a plug sized to fit in said sheath, a flange on one end of said plug, a necked-down portion on said plug adjacent said flange, a central passageway through said plug and flange, a sleeve sized to receive said flange and said sheath, means on said sleeve for cooperating with said flange and engaging said sheath to retain said sleeve in longitudinally oriented sliding engagement with said flange and said sheath when received thereon, said plug being forced into an end of said sheathed conductor beneath said sheathing to a position with said flange abutting the end of said sheath whereby said conductive core is displaced at the position of said plug and extruded into said passageway in contact with said plug, sealing means in said passageway whereby external access to said conductive core is prevented, said sleeve overlying said flange and the end of said sheath whereby relative rotation of said sleeve with respect to said flange and said sheath is prevented, and said sheath being contracted about said necked-down portion on said plug whereby relative longitudinal movement of said plug and sheathed conductor is prevented.

5. A cable termination for a sheathed conductor including an elongated conductive core and a tubular sheath laterally enclosing said core, which termination includes a plug sized to fit in said sheath, a flange on one end of said plug, a sleeve sized to receive said flange and said sheath, means on said sleeve for cooperating with said flange and engaging said sheath to retain said sleeve in longitudinally oriented sliding engagement with said flange and said sheath when received thereon, means for securing said sleeve to said flange, said plug being positioned in an end of said sheathed conductor in contact with said conductive core with said flange abutting the end of said sheath, and

said sleeve overlying said flange and the end of said sheath whereby relative rotation of said sleeve with respect to said flange and said sheath is prevented.

6. A cable termination according to claim 5 in which said means on said sleeve includes a spline disposed lengthwise of said sleeve on the interior thereof and in which said flange includes a groove receiving said spline.

7. A cable termination according to claim 3 in which said sealing means includes a shoulder on said plug in said passageway, a plug in said passageway seated against said shoulder on the side thereof facing the flanged end of said first-named plug, and means securing said secondnamed plug to said first-named plug.

References Cited UNITED STATES PATENTS 2,659,795 11/1953 Boggs 17475 3,109,691 11/1963 Burkhardt 174-75 X LEWIS H. MYERS, Primary Examiner.

H. HUBERFELD, A. T. GRIMLEY,

Assistant Examiners. 

